1. Field of the Invention
The invention relates to the field of medical sensors and, in particular, to the field of temperature sensors for patients combined with a spirometer.
2. Description of Related Art
During emergency treatment of a patient, two of the important physical parameters that the physician must know are the temperature and respiration rate of the patient. In addition, any device or combination of devices must be portable so that it can be used in the field, for example, the seen of an accident. There are numerous portable spirometers available. For example U.S. Pat. No. 5,383,470 "A Portable Spirometer" by K. Kolbly, filed Sep. 30, 1993 (common inventor and assignee) discloses a simple spirometer which allow the patient to breathe there through. Another example can be found in U.S. Pat. No. 3,735,752 "Spirometer" by J. A. Rodder. In both these portable devices one end of the spirometer is inserted into the mouth of the patient who breaths there through and the respiration rate is automatically displayed. There are also numerous electronic type temperature sensors such as disclosed in U.S. Pat. No. 5,211,479 "Digital Pacifier Thermometer" by F. Coffey, et al. This electronic device uses a series of electrical temperature sensors mounted on the end of a child's nipple shaped pacifier. The electronic circuit is capable of comparing the measurement of each temperature sensor and selects the highest stable reading and displays it. However, the patient must breathe through the nose.
There are also numerous devices for simultaneously measuring the respiration rate and temperature of the patient. For example U.S. Pat. No. 3,884,219 "System For Determining Temperature And Respiration Rate" by P. C. Richardson, et al. and U.S. Pat. No. 4,222,391 "Unitary Disposable Sanitary Sheath For Temperature And Respiration Sensing Probe" by P. O. Rawson, et al. In both these devices a housing is included having a hollow tube that is inserted into the mouth. The housing also includes a cup shaped member that is positioned under the nose of the patient to sense respiration rate therethrough. A temperature probe is inserted through the housing and into the mouth to measure temperature. U.S. Pat. No. 3,999,537 "Temperature, Pulse And Respiration Detector" by D. G. Noiles discloses a combination pulse temperature and respiration detector. However, while the temperature and pulse sensors are mounted on a probe that is inserted into the mouth, the respiration rate is measured by sensing air flow from the nose. While these devices will measure both temperature and respiration rate, they do not allow for the simultaneous delivery of oxygen. In addition, if the patient's nasal passageways are closed, due to a cold, respiration rate measurements are not possible.
In U.S. Pat. No. 4,510,941 "Temperature, Pulse And Respiration Mouthpiece Probe" by C. M. Semrow all three measurements are made by probes within the mouth. However, the respiration rate is sensed by a photodetector that operates like a photplethysmograph. That is, it depends upon the photodetector sensing changes in the reflectivity of the interior of the patients mouth that changes with the pulse rate as well as the respiration rate. The same sensor is used to make both readings and electronic circuitry is used to differentiate pulse rate from the slower respiration rate. This device also does not allow for the patient to receive oxygen while taking measurements. In addition, the measuring the reflectivity of the mouth is suspect.
Thus it is a primary object of the invention to provide a temperature sensor that allows patients to breathe through their mouth as the temperature is measured.
It is another primary object of the invention to provide a combination spirometer and temperature sensor.
It is a further object of the invention to provide a combination spirometer and temperature sensor that allows the patient to simultaneously breath through the mouth.
It is a still further object of the invention to provide a combination spirometer and temperature sensor that allows the patient to simultaneously receive oxygen.